MiRNA-145-5p inhibits gastric cancer progression via the serpin family E member 1- extracellular signal-regulated kinase-1/2 axis.

BACKGROUND: MicroRNAs (miRNAs) regulate gene expression and play a critical role in cancer physiology. However, there is still a limited understanding of the function and regulatory mechanism of miRNAs in gastric cancer (GC). AIM: To investigate the role and molecular mechanism of miRNA-145-5p (miR145-5p) in the progression of GC. METHODS: Real-time polymerase chain reaction (RT-PCR) was used to detect miRNA expression in human GC tissues and cells. The ability of cancer cells to migrate and invade was assessed using wound-healing and transwell assays, respectively. Cell proliferation was measured using cell counting kit-8 and colony formation assays, and apoptosis was evaluated using flow cytometry. Expression of the epithelial-mesenchymal transition (EMT)-associated protein was determined by Western blot. Targets of miR-145-5p were predicated using bioinformatics analysis and verified using a dual-luciferase reporter system. Serpin family E member 1 (SERPINE1) expression in GC tissues and cells was evaluated using RT-PCR and immunohistochemical staining. The correlation between SERPINE1 expression and overall patient survival was determined using Kaplan-Meier plot analysis. The association between SERPINE1 and GC progression was also tested. A rescue experiment of SERPINE1 overexpression was conducted to verify the relationship between this protein and miR-145-5p. The mechanism by which miR-145-5p influences GC progression was further explored by assessing tumor formation in nude mice. RESULTS: GC tissues and cells had reduced miR-145-5p expression and SERPINE1 was identified as a direct target of this miRNA. Overexpression of miR-145-5p was associated with decreased GC cell proliferation, invasion, migration, and EMT, and these effects were reversed by forcing SERPINE1 expression. Kaplan-Meier plot analysis revealed that patients with higher SERPINE1 expression had a shorter survival rate than those with lower SERPINE1 expression. Nude mouse tumorigenesis experiments confirmed that miR-145-5p targets SERPINE1 to regulate extracellular signal-regulated kinase-1/2 (ERK1/2). CONCLUSION: This study found that miR-145-5p inhibits tumor progression and is expressed in lower amounts in patients with GC. MiR-145-5p was found to affect GC cell proliferation, migration, and invasion by negatively regulating SERPINE1 levels and controlling the ERK1/2 pathway.

Efficacy of thalidomide for refractory gastrointestinal bleeding from vascular malformation.

BACKGROUND & AIMS: Patients with recurrent bleeding from gastrointestinal vascular malformations are a challenge to treat. We investigated the long-term efficacy and safety of thalidomide for refractory bleeding from gastrointestinal vascular malformations in an open-label, randomized study. METHODS: Eligible patients were randomly assigned to groups that were given either 100 mg thalidomide (n = 28) or 400 mg iron (n = 27, controls), daily for 4 months; patients were followed for at least 1 year (mean, 39 months). Bleeding was defined by a positive result from an immunoassay fecal occult blood test. The primary end point was the effective response rate, defined as the proportion of patients in whom bleeding episodes had decreased by ≥ 50% in the first year of the follow-up period. The secondary end points included the rates of cessation of bleeding, blood transfusion, overall hospitalization, and hospitalization for bleeding. We also quantified yearly bleeding episodes, bleeding duration, levels of hemoglobin, and yearly requirements for transfusions of red cells, numbers of hospitalizations for bleeding, and hospital stays. Plasma levels of vascular endothelial growth factor were measured in the group given thalidomide. RESULTS: Rates of response in the thalidomide and control groups were 71.4% and 3.7%, respectively (P < .001). All secondary end points differed significantly different between groups; thalidomide was more effective. No severe adverse effects were observed, although minor side effects were common among patients in the thalidomide group. Levels of vascular endothelial growth factor were significantly reduced by thalidomide (P < .001). CONCLUSIONS: Thalidomide is an effective and relatively safe treatment for patients with refractory bleeding from gastrointestinal vascular malformations. Mechanisms of thalidomide activity might involve vascular endothelial growth factor.

Inhibition of invasion and metastasis of gastric cancer cells through snail targeting artificial microRNA interference.

The zinc-finger factor Snai1 plays an important role in the down-regulation of E-cadherin expression and in the induction of epithelial-mesenchymal transition (EMT) during cancer progression. In gastric cancer tissues, we noted that Snail is abnormally high expressed and is remarkably associated with the lymph node metastasis. Using a plasmid containing newly synthesized artificial microRNA (amiRNA), we transfected gastric cancer cells to block Snail expression. Both Snail protein and mRNA levels were significantly decreased in stably transfected cells, while protein and mRNA expression of E-cadherin was up-regulated. In addition, migration and invasion potential were significantly decreased after knockdown of Snail.

[The mechanisms of thalidomide in treatment of angiodysplasia due to hypoxia].

OBJECTIVE: To investigate the inhibitory effect of thalidomide on angiodysplasia. METHODS: Excisional intestinal specimens were collected and immunohistochemical examination was carried out. The human umbilical vein endothelial cells were cultured in vitro to exponential phase of growth, divided into six groups and synchronized for 24 hours. They were then stimulated with thalidomide (40 - 100 microg/ml) for 72 hours. MTT assay was used to assess cellular proliferation. ELISA, real-time quantitative PCR and western blot were applied to detect the expression of VEGF/HIF-1alpha of human umbilical vein endothelial cells (HUVEC). RESULTS: Immunohistochemical analysis of intestinal pathological specimens demonstrated higher expression of VEGF. ELISA showed that the expression of VEGF under hypoxia was obviously higher than that under normoxia [(1199.3 +/- 61.4) ng/L vs (864.7 +/- 41.2) ng/L, P < 0.05]. Real-time quantitative PCR and Western blot discovered that thalidomide inhibited the expression of VEGF/HIF-1alpha of HUVEC (P < 0.05). The effect of thalidomide was dose-dependent. CONCLUSIONS: Thalidomide can suppress the expression of HIF-1alpha and VEGF in HUVEC in vitro and then inhibit angiodysplasia, which may play a significant role in stopping the rebleeding in patients with recurrent gastrointestinal bleeding.

[Nuclear gene involves in phenotype of non-syndromic deafness associated with mitochondrial 12S rRNA mutation].

The human mitochondrial 12S rRNA gene mutation at position 1555 associated with non-syndromic deafness and aminoglycoside-induced deafness. Family of Huaiyin in Jiangsu is one of the biggest non-syndromic deafness family in the world. In this family, deafness is maternally inherited. After establishing immortal lymphoblastoid cell lines of the family by EB virus, we analysed 17 lymphoblastoid cell lines derived, respectively, from symptomatic, asymptomatic and controll members of the family. Compared with control members, symptomatic and asymptomatic members both exhibited significant decreases in the rate of growth as well as in the rates of mitochondrial protein synthesis. But the extent of decreases is different and the severity of mitochondrial defect is related with its clinical phenotype. These results supported that the nuclear factor involves in the phenotypic manifestation of the non-syndromic deafness associated with the A1555G mutation.

[Sequence analysis of the connexin 26 genes from a deafness family with A1555G mutation in Huaiyin].

OBJECTIVE: To ascertain whether connexin 26 (Cx26) gene was a nuclear modifier gene in an extensive family with matrilineal nonsyndromic deafness associated with A1555G mutation in Huaiyin, China. METHODS: Following PCR-restriction fragment length polymorphism (PCR-RFLP) with ApaI restriction enzyme, Cx26 genes from 26 cases, with A1555G mitochondrial mutations in this family, and 62 controls (including 2 patrilineal relatives, 10 spouse controls and 50 unrelated controls), were sequenced. RESULTS: Compared with the reference sequence of Cx26 gene, totally four kinds of nucleotide changes,79G -->A, 109G-->A, 341G-->A and 235delC, were detected in a heterozygous form. However, the former three were previously reported polymorphisms, and only the 235delC was a previously described recessive mutation associated with most autosomal nonsyndromic sensorineural hearing loss in Japan and China. Further study showed that the heterozygous 235delC mutation existed in both one individual with mild hearing loss and two individuals with normal hearing. Clinical characterization showed that 235delC mutation did not seem to modify the deafness phenotype due to the A1555G mutation. Moreover, this 235delC mutation was deduced to derive from a married-in control. Finally, there were no co-segregation between the phenotypes of hearing loss and the genotypes for Cx26 genes based on the four kinds of nucleotide changes. CONCLUSIONS: The heterozygous 235delC mutation of the Cx26 gene may not modulate the severity of hearing loss associated with A1555G mutation and Cx26 gene is unlikely to be a modifier gene for hearing loss due to A1555G mitochondrial mutation in this Chinese family.

Sequence analysis of the mitochondrial genome from a large family with maternally inherited nonsyndromic deafness.

OBJECTIVE: To ascertain whether other variations coexist with 1555(A--> G) mutation in the mitochondrial DNA and may aggravate the severity of hearing loss or increase the penetrance of 1555(A--> G) mutation in a large family with maternally inherited nonsyndromic deafness in Huaiyin, Jiangsu province. METHODS: PCR-restriction fragment length polymorphism (PCR-RFLP) was used to screen both the nt1555 and the nt7445 of the mitochondrial DNA from 27 maternal members in the core family; and then the mitochondrial genomes from two maternal members, and the 12S rRNA genes MTRNR1 and tRNA-Ser(UCN) gene MTTS1 from the others, were amplified by PCR-RFLP and were sequenced. RESULTS: 1555(A--> G) mutation in the mitochondrial DNA was reverified to be one of the major factors which cause maternally inherited nonsyndromic deafness and the cosegregation of 955-960(insC) and 1555(A--> G) was present in this family. Moreover, 7449 (insG), a novel homoplasmic mutation in the tRNA-Ser(UCN) gene, was found to co-exist with 1555(A--> G) mutation in two maternal members. CONCLUSION: The cosegregation of 955-960(insC) and 1555(A--> G) implies that 955-960(insC) may synergistically cause hearing loss in the presence of an 1555(A--> G) mutation, serving as an aggravating factor to enhance the sensitivity to aminoglycosides, and may sometimes increase the penetrance of 1555(A--> G) mutation.

[Establishment of Immortal Lymphoblastoid Cell Lines of Non-syndromic Deafness Family and Several Methods fro Transforming Human B Lyphocyte by EB virus.].

Reservation of rare family materials is the base for us to do further research. Family of Jiang-Su Huai-Yin is one of the biggest non-syndromic deafness families in the world. In this family,deafness is maternally inherited and all the sufferers have the mitochondrial DNA 12s RNA A1555G mutation. Four methods are used in the experiments for establishing immortal lymphoblastoid cell lines of the family with non-syndromic deafness. Results were as follows: 1 cell line was from small amout of whole blood method, 1 cell line from frozen whole blood method, 14 cell lines from frozen leukocyte method, and 36 cell lines from cyclosporin A method. In this paper, we will discuss these four methods through our experiments of establishing cell lines.